How a 1C temperature shift is changing UK climate: significance, effects - and the impact if warming continues

If global warming reaches 2C the UK can expect the likes of heatwaves and droughts to become the “new normal”, experts warn

The UK is facing a continuation of warmer than average years with heatwaves becoming more severe.

The most recent decade was 1C warmer than the 1961-1990 climate period and this is influencing the conditions the country is currently experiencing.

In July a record temperature of 40C was reached for the first time, with the extreme heat being far more intense and widespread than previous comparable heatwaves, according to the Met Office.

An environment expert told NationalWorld that an increase in temperature of just 1C is “very important and significant”, shifting not only our climate but ecosystems and sea levels.

How is a 1C temperature shift changing the UK climate?

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The latest annual report from the Met Office shows the impact of global temperature rises on the climate in the UK - reaffirming climate change is not just a problem for the future.

The report said the maximum temperature recorded in 2021 was 32.2C, which is considerably warmer than the average hottest day of the year for the period 1961-1990 of 31.4C.

The global average temperature is also now over 1.2C warmer than before the industrial revolution when the widespread burning of fossil fuels began.

Professor Richard Betts, head of climate impacts research at the Met Office and University of Exeter, explained: “This is causing UK weather to be generally warmer on average, and with heatwaves being more severe.

“On 19July, temperatures exceeded 40C across much of England – these temperatures here would have been virtually impossible without the world having been warmed.

“More severe heatwaves are also making droughts more severe – the landscape is dried out faster by evaporation, magnifying the impacts of lack of rain.

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“This in turn increased the risk of wildfires – when fires start, the tinder-dry landscape means they rapidly become much more severe.”

Mike Kendon, from the Met Office National Climate Information Centre and lead author of the report, said weather events last year put into context how much a 1C rise is significant.

This includes Storm Arwen in November, Storm Darcy in February, a new Northern Ireland temperature record in July and exceptional rain in October.

Mr Kendon said: “When considering the UK climate over the whole year it might seem rather unremarkable, however it is telling that whereas we consider 2021 as near-average for temperature in the context of the current climate, had this occurred just over three decades ago it would have been one of the UK’s warmest years on record.”

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Mariam Zachariah, from the Grantham Institute for Climate Change, Imperial College London, said a 1C average temperature rise “implies hotter summers and warmer winters, along with increased likelihoods of heatwaves and lesser chances of frosts and cold spells.”

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She said: “A warmer atmosphere holds more moisture, thus intensifying precipitation.

“However,  this ‘thermodynamic effect’ may be offset or supplemented by the various atmospheric circulation systems that drive precipitation in these parts, thus making it more difficult to discern the effects of warming on precipitation.”

Is a 1C temperature change significant?

Climate experts told NationalWorld that a 1C temperature change is “very important, and significant”, as it is causing more heatwaves, heavy rain, severe droughts and also contributing to a substantial sea level rise which will continue for centuries.

Professor Betts said: “Many species of plants, animals and insects are being affected by a warmer climate.

“Signs of spring are coming earlier, such as the emergence of leaves, flowers, and insects, the hatching of eggs and the arrival of migratory birds.

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“Many species are also starting to shift to new locations which were previously cooler, in order to stay within the local climates to which they are adapted.”

Ms Zachariah added that “every increment in temperature is significant”, and the UK should expect temperature changes to occur more often.

She said: “Considering the effects on temperature itself, we should expect temperatures that we were previously unaccustomed to, to occur more often, requiring immediate adaptation strategies, along with long-term mitigation.

“For example, the need for retrofitting existing infrastructure and revising building codes in the UK has been one of the points discussed widely during this year’s heatwave.

“Sudden increases in temperatures causing premature ripening of berries, and the compounding impacts of rising temperature and precipitation shortfalls on agriculture are other examples.”

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What will happen if average temperatures continue to rise?

Professor Betts told NationalWorld that the consequences would be stark if global warming does continue to increase.

He said if global temperatures reach 2C “we can expect to see up to a 20% reduction in water resources, and very high fire risk about 25% of the time in summer.

He added: “We can also expect to see ongoing rises in sea level around the coast, threatening coastal communities in low-lying areas.”

Mr Kendon agreed, saying that while 1C of warming “might not sound like much, it has led to maximum temperatures like the 32.2C we saw in 2021 becoming routine rather than the exception.

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“This is particularly stark when considering the record breaking heat the UK experienced.”

Ms Zachariah also warned that the UK will see more extreme weather more frequently, with the likes of heatwaves and droughts becoming the “new normal”.

She said: “We can expect the chances of hot extremes, droughts and heavy precipitation to increase, and shift to new normals.”